Spring 2011

Our intern, Ali - an undergraduate student from Middlebury College, details her experiences from her summer with the HOT program.

Wednesday, April 20, 2011

Weaving Tangled Dreams

Yesterday, Craig sent me a link to a branch of the HOT website which displays Acoustic Doppler Current Profiler (ADCP) data from past cruises.  Anyone can come to this site to look through plots of current velocity and direction recorded by the ADCPs aboard the Kilo Moana or the Ka`imikai-o-Kanaloa.  Despite its noble attempts to make cruise data available to the masses, this is the ugly duckling of websites. Its first offense is its background color: beige, the internationally recognized color for blandness.  It also hasn’t been updated with new data for a while and has some functionality issues.

With the link to this website, Craig gave me the task of giving the ugly duckling a makeover.  However, the extent to which I am able to name the flaws of the ADCP page is equaled by my inability to fix them.   Dreamweaver, the software that I am using to redesign the page, has its own language wholly different from the other computer languages I have previously mentioned.   My learning process involves many trials and even more errors.  Edit > Undo is my savior as I accidentally turn the page upside time after time. My limited successes so far include inserting links to anchors on the page, or to other html files, resizing and aligning images, and my greatest triumph: changing the background color from beige to blue.
One of my successes: cropping an image.
At some point in the afternoon, after too many Edit > Undo’s for one day, Craig gave me a new project. Though this project still involves an unknown language, that of Matlab, it comes more logically to me. On the cruise last week, heave compensation was used for the first time during the casts in order to let the CTD descend more smoothly.  This means that the winch lets out the wire at varying speeds depending on the heave of the boat in order to keep the tension on the wire relatively constant. What remains to be seen about heave compensation is how accurately it reports the speed at which the CTD descends. This is where my project begins: I will use Matlab to plot wire speed from the winch over time and compare it to the pressure versus time data from the CTD.  This will show how accurate the winch data is, as well as show how beneficial the heave compensation is.

To the first twenty commands I tried, Matlab stubbornly refused to acquiesce. Matlab is quite particular, I have learned, about the use of parentheses and colons. It is training me quickly to pay attention to these details. Success came slowly and even the simplest plot gave me great satisfaction. Craig introduced me to the m-file, a text document in which I can record all of my commands and explain their functions, with whom I got along much better than with Matlab itself.  With a couple of magic movements from Craig’s fingers, Matlab ran the functions in my m-file and out popped 2 new plots. I aspire to Craig’s magic fingers someday. In the meantime, the Matlab vocabulary lessons continue:

‘pwd’               stands for ‘print working database’ which means ‘where am I?’  to which the answer is invariably an address to a database which I do not understand. I’ve got the question down, though.

1 comment:

  1. I wouldn't call them "magic". It's just that Matlab has made me bang my head on my desk so many times that my fingers had to take over for my brains.